MOGADISHU, Somalia -- A U.S. military drone strike on a vehicle carrying explosives in Somalia has removed "an imminent threat to the people of Mogadishu" by the al-Shabab extremist group, the U.S. Africa Command said Tuesday.

The airstrike was carried out early Tuesday morning about 65 kilometers (40 miles) southwest of Somalia's capital, the U.S. statement said, adding that no civilians were killed. It was not immediately clear how many al-Shabab fighters may have been killed.

A senior Somali intelligence official said the airstrike largely destroyed a minibus traveling near the rebel-held village of Mubarak in Lower Shabelle region. The official spoke on condition of anonymity because he was not authorized to speak to the media.

The al-Qaida-linked al-Shabab has been blamed for the massive truck bombing in Mogadishu in October that killed 512 people, wounded more than 300 others and left more than 60 missing. Only a few attacks since the ones on Sept. 11, 2001 have killed as many people, according to the Global Terrorism Database at the University of Maryland.

Al-Shabab, the deadliest Islamic extremist group in Africa, often targets high-profile areas of Mogadishu including hotels, military checkpoints and the presidential palace.

The U.S. military has carried out 32 airstrikes this year against the Somalia-based al-Shabab and a small but growing presence of fighters linked to the Islamic State group. The Trump administration early this year approved expanded military operations against extremists in the Horn of Africa nation, as the Trump administration puts counterterrorism at the top of its foreign policy agenda for Africa.

More than 500 U.S. military personnel are now in Somalia, the U.S. Africa Command said last month.